The present invention relates generally to the field of motor control centers and similar power electronic systems, and more particularly to novel techniques for providing EtherNet and Internet connectivity in such devices.
Motor control centers (MCCs) are common throughout a range of industrial and automation applications. In general, although referred to as motor control centers, these devices group a range of equipment for a variety of electric loads, and commonly include switchgear, automation control equipment, and supporting circuits into manageable cabinets that can be positioned at various locations around a controlled machine or process. The cabinets typically include individual compartments or bays that can be accessed through lockable doors. Because the components within MCCs often regulate application of three-phase power to loads, access to the interior of the bays, and routing of data within the devices needs to be specially controlled and adapted for the high voltage environment.
In conventional MCCs three-phase power is typically routed to the switchgear and control devices through bus bars that extend horizontally and vertically in a backplane of the cabinet. The component bays can plug into these bus bars to draw power from a line side supply, typically connected to the utility grid. Controlled output power for various loads, such as electric motors, may be routed through dedicated wireways in various areas of the cabinet. A particular challenge entails the routing of data within the enclosures and between the components within the various bays. Conventional MCCs often utilize open industrial data exchange protocols that have dedicated physical media for the exchange of data used for control, reporting, and other purposes.
While these approaches have been largely sufficient in the past, standardization on more commonly available protocols is necessary. For example, components have, in the past, been adapted for communication in accordance with specific industrial protocols, with chip sets, software and firmware specifically adapted for these. The data exchange media in the MCC cabinet has similarly been adapted according to industrial standards. Little or no development, however, has been made for Internet-based connectivity and particularly for connectivity using a standard EtherNet protocol. Problems persisting in the area relate to how most efficiently to distribute the Internet or EtherNet communications within MCC cabinets, making it available for individual components within individual bays. There is a need, therefore, for improved connectivity solutions that can allow for the use of Internet and EtherNet protocols in the context of MCCs.